<!DOCTYPE HTML>
<html>
  <head>
    <meta http-equiv="content-type" content="text/html" charset="utf-8">
    <title> CSS 样式学习</title>
    <style media="screen" type="text/css">
      h1{
        /**这是个css的注释**/
        background-color: #000000;
      }
    </style>
  </head>
  <body>
    <h1 style="text-align:center;font-size:20px;color:#00ff00;">这是一个你看不见的css的注释</h1>
  </body>
</html>
